Something similar is happening to me.
Here is what I have:
Wiikey on a 1st gen Wii NTSC-U
burning using Img burn 2.3.2
I used DVDinfo and tried settings with book types:
for DVD+R DL set at DVD+RDL and DVD-ROM both did not work.
My burner is LG GH20NS10
I used Philips DL DVD+R burned on 2.4 speed.
The game (burnt with DVD-ROM book type) went through the update process fine, however once it restarted it got to the opening screen where it has the panning shot of all the characters. It then freezes to a white screen and comes up with a message saying the wii cannot read the media or something along those lines.
The game burnt with the DVD+RDL booktype freezes at the loading screen I believe.
Could it be my media? I will be testing out on the weekend if Verbatims will work better but I'd still like to know if I am doing anything wrong in my process. Any help would be greatly appreciated.